The present invention relates to an electrophotographic coping process and more specifically to a method of reducing or enlarging an image by adjusting the positioning of a focusing lens assembly.
As is well known to those skilled in the art, the electrophotographic process is characterized by such basic steps as charging a photo-sensitive drum, exposing the drum to form a latent electrostatic image, developing the latent image with toner and transferring the developed image to a paper or the like.
In the conventional electrophotographic copy machine of small size or of medium size, there have been employed either one of two scanning methods for forming a latent image of an original on the photo-sensitive drum as follows:
(a) The platen holding an original is moved relative to the fixed optical-fiber-lens to scan the original, and the image of the original is exposed onto the drum via the optical-fiber-lens to form the latent image thereof, and
(b) The mirror system is moved relative to the fixed platen to scan the original, and the image of the original is exposed onto the drum after passing through the focusing lens to form the latent image thereof.
In the copy machine of the type mentioned above, mechanical vibrations are caused due to the movement of the platen or the mirror system, especially when the direction of the movement is reversed. These vibrations are not too magnified when the copying speed is low.
However, in a copy machine having a higher copying speed, it becomes difficult to absorb such vibrations with the body of the machine and, therefore, blurring of the image is realized due to the vibrations.